Apparatus for agglomerating ores



E. W. DAVIS.

APPARATUS FOR AGGLOMERATING ORES.

APPLICATION FILED NOV. 19, 1918. 1,350,440, Patented Aug. 24, 1920.

8 3 SHEETS SHEET l.

E. W. DAVIS.

APPARATUS FOR AGGLOMERATING ORES.

APPLICATION FILED NOV. 19. I918.

E. W. DAVIS.

APPARATUS FOR AGGLOMERATING 0R ES. APPLICATION FILED NOV. 19. 1918.

1,350,440. P nted Aug. 24, 1920.

3 SHEETSSHEET 3.

UNITED STATES EDWARD W. DAVIS, OF DULUTH, MINNESOTA.

APPARATUS FOR AGGLOMERATING ORES.

Specification of Letters Patent.

Patented Aug. 24, 1920.

Application filed November 19, 1918. Serial No. 263,130.

To all whom it may concern:

Be it known that I, EDWARD I/V. DAVIS, a citizen of the United States, residing at Duluth, in the county of St. Louis and State of Minnesota, have invented certain new and useful Improvements in Apparatus for Agglomerating Ores, of which the following is a specification.

This invention relates to improvements in apparatus for agglomerating ores and other substances by means of heat; and its principal object is to simplify and increase the eiiiciency of apparatus designed for that purpose.

The process of sintering ores is usually carried on by mixing the finely powdered moist ore with powdered fuel, placing the mixture in a suitable container, and gradually burning the fuel mixed with the ore while subjecting the contents of the container to a blast of air, or to suction, in order to carry the combustion through the ore or other material. In one prior form of apparatus a series of connected taveling pans or cars is employed, and these cars are caused to pass in succession over a wind box, in order to cause a current of air to pass through the'charges of ore in the cars. To prevent the loss of air and secure the necessary velocity and volume of air through the sintering charge, it has been necessary in this prior apparatus to allow the separate cars to make a sliding or rubbing contact with the top or side of the wind box. This contact is never perfect, and a serious loss of air occurs, while at the same time the contacting parts rapidly wear off, due to the dust and grit which is always present. This arrangement also causes a considerable increase in the consumption of power required to move the cars forward. In this prior apparatus less than half of the total numher of cars are actually sintering ore at a given time, since the remaining cars are being carried back empty to the loading position, whereby a large, heavy, and expensive construction is necessary. In a second prior form of sintering apparatus a small number of single pans are used in connection with individual operating apparatus, and these pans are mounted to revolve on trunnions, so that the construction in that form also is heavy and expensive.

I have discovered that it is possible to do away with heavy and expensive apparatus,

and to use cheaply constructed sintering units, of light weight and without expensive machined parts or surfaces, and without the use of a cumbersome or expensive supporting structure. An important feature of the present invention is that the apparatus may be built on the ground, if desirable, and the cars moved about with a minimum consump tion of power. An important object is to provide apparatus for agglomerating ores in which there is no leakage or loss of air, and no sliding contact or other mechanical seals for preventing leakage. The present lnvention employs a Water or other liquid seal, in combination with improved means for causing the cars to enter the seal sucoessively and establish communication with a vacuum chamber, by which the air is drawn through the sintering chambers contained in the successive cars. Other objects of the invention relate to various features of construction and arrangement which will appear more fully hereinafter.

The nature of this invention will be understood from the following specification, taken in connection with the accompanying drawings, in which one embodiment is illustrated.

In the drawings Figure 1 shows a top plan view of my improved sintering apparatus;

Fig. 2 shows a side elevation of the apparatus illustrated in Fig. 1;

Fig. 3 shows an enlarged longitudinal sectional View, taken on the line 33 of Fig. 1;

Fig. 4 shows an enlarged transverse sectional view through one of the sintering cars and the vacuum chamber, taken on the line 4l4 of Fig. 1; and

Fig. 5 shows a plan view of the water seal and tank, and-the gates through which the vacuum pipes of the cars pass into connection with the vacuum chamber.

In carrying out the invention a series of individual cars are used, and these cars are mounted on an oblong track for movement in succession past a vacuum chamber of relatively great length. The cars are loaded at one end of the oblong track, and they then pass in succession into connection with the vacuum chamber, whereby a current of air is drawn through the mixture of ore and fuel in each car. The charge in each car is ignited immediatelyv after the car passes into connection with the vacuum chamber and the suction of air causes the zone of combustion to pass downwardly from the upper surface to the grates at the bottoms o the cars. Each car remains in connection with the vacuum chamber throughout 12, and 13, the center rail being curved outwardly at each end of the track to effect the turning movements of the cars by engagement with the trailing wheels thereof. A

plurality of individual cars or trucks 15 are mounted on the track 10, and adapted to carry the charges of material to be sintered through the various stages of the sintering process, as summarized above.

Each of the cars 15 is of the construction shown particularly in Figs. 3 and 4, and includes a sheet metal box 16, of rectangular form, having mounted in the lower part thereof a metallic grate 17 which has a plurality of upwardly converging apertures 17 therethrough, and is provided around its lateral edge with a depending flange 17 adapted to rest on the lower wall 18 of the box. Filler plates 19 are mounted within and seated against the side walls of the box 16, and these filler plates have downwardly and inwardly inclined inner surfaces, so

that the cross section of the box at the grate is much less than its cross section around the upper edge. The sloping walls allow for shrinkage as the sintering progresses, so that leakage of air around the outside edges of the charge is prevented. The sloping walls also permit the sintered contents of the car to be easily dumped by tilting the car to an inclined or inverted position. Each of the boxes 16 is mounted upon and secured to an axle 20, and this axle carries at its ends flanged wheels 21, which are adapted to travel upon the outer rails 11 and 13, previously described. The axle is located forwardly of the center of each box, and the rear end of the box carries at its center a.

flanged wheel 22 which travels upon the central rail 12. This trailing wheel is mounted in a bracket 23, which is pivoted to swing about a vertical axis on a plate 24 attached to the under side of the box. The flange 17 of the grate serves to space the grate proper from the lower wall 18, thus forming an air chamber, which is connected throughout the width of the box forwardly of the axle 20 with a vacuum pipe 25. This vacuum pipe is closed at one end, but extends outwardly at the other side of the car, and is provided on the end thereof With a downwardly depending U-sha ed tube 26, which terminates in an upwar 1y extending outlet ipe 27.- This U-shaped tube 26 is ada te to enter a water seal, and the pipe 27 orms a communication with a vacuum chamber, as hereinafter described.

The water seal is formed by a long rectangular tank 30, which lies parallel to the oblong track 10 at one side thereof, as illustrated in F ig. 1. The lower wall of the tank is provided with a downward extension 31, of semi-circular cross section, which extends throughout the length of the tank and is adapted to receive the U-shaped portion 26 of the'vacuum tube when the latter is in communication with the vacuum chamber. The vacuum chamber comprises a tubular conduit 32, which is mounted above the tank 30 and which has two downwardly extending walls 33 and 34. The wall 33 is continuous with one wall of the tank 30, and the other wall 34 is adapted to extend downwardly into the water between the opposite arms of. the U-shaped tube. The angular portion 26 of each of the vacuum pipes is provided with a downwardly extending b ade or scraper 35, which is adapted to travel above the wall of the semicircular extension 31 of the tank, in order to remove the sediment therefrom, as hereinafter described. A spray tube 36 is mounted in the upper part of the tubular portion 32 of the vacuum chamber, and is connected to a water supply pipe 37 controlled by a valve 38, so that the gases of combustion may be partially cooled and con-- densed and the sediment removed therefrom when the apparatus is in operation. The air .is exhausted from the chamber 32 through a pipe 39 connected to a centrifugal vacuum pump 40, which is driven by a motor 41, as illustrated particularly in Fig.

In order to pass the cars into connection with the water seal, the rails of the track are elevated at the point 45, as shown in Fig. 2, so that as each car passes this point it is elevated sufiiciently to carry the lower portion of the U-shaped tube 26 and scraper 21 over the end wall 30 of the tank. The lower part of the U-shaped tube is then immersed in the water within the tank, and upon further forward movement of the car the U-shaped tube passes into connection with the vacuum chamber through a vestibule 46, which is in the form of a rectangular closed chamber, one side wall of which is a continuation 34'' of the wall 34 of the vacuum chamber, while the other side of the wall 47 is spaced outwardly from the side wall 33 and forms a lateral extension of the tank 30. This vestibule is in communication at one end with the vacuum chamber, and is open' at the other end to communicate with the tank. .A pair of gates 49 and 50 extend transversely of the .vestibule 46, and are mounted to swing on vertical pivots 49f and 50, respectively, which rotate in su1table bearings carried by the upper and lower walls of the vestibule. The opposite edges of these gates are adapted to seat against the oppositely disposed cleats 51, and each gate is opened by movement about its pivots in an anti-clockwise direction, as viewed in Fig. 5. The shafts 49 and 50 extend up through the upper wall of the vestibule, and have fixed thereon the crank arms 52 and respectively, which are connected by a COll spring 54. This coil spring is normally under tension, and tends to maintain the gates in closed positions by its action upon the oppositely directed crankarms 52 and 53, which are parallel to each other and directed in opposite directions from their shafts.

As one of the cars moves in a forward direction on the track toward the right, as viewed in Fig. 5, the outlet 27 of the vacuum tube passes into the vestibule and engages the inner side of the first gate 49, which is then pushed to an open position permitting the pipe to pass therethrough, as illustrated by dotted lines in Fig. 5. Then the gate 49 opens the tension of the spring 54 is increased, thus maintaining the gate 50 in a closed position, while at the same time exerting upon the gate 49 an increased force tending to close it. After the pipe 27 has passed the gate 49 the spring automatically closes that gate, and upon further travel of the car the pipe 27 engages the gate 50 at one side of the pivot thereof, and causes that gate to open against the tension of the spring. The spring during this time maintains the gate 49 in a closed position, so that the vacuum is maintained in the vacuum chamber when the gate 50 opens. After passing the gate 50, the outlet 27 is in direct communication with the vacuum chamber, as illustrated in Fig. 4, and a suction is then exerted on the contents of the car.

At the opposite end of the vacuum chamber the vacuum tubes pass out of connection therewith through an exit chamber 56, which is similar to the vestibule 46, being provided with two pivoted gates which are adapted to swing in only one direction, and are connected to each other by means of crank arms 57 and 58, and a coil spring 59. The tank 30 projects beyond the vestibule 56, and at this point the track 10 is inclined upwardly, as shown at 60, so that the cars pass upwardly, and the lower portions of the U- shaped tubes 26 are carried over the end wall 30 of the tank. Immediately after passing a substantially vertical position, and the contents thereof pass downwardly between the rails 11 and 13. The rear wheel 22 of the car then passes on to an inclined portion 62 of the center rail 12, and the car is elevated again into its normal position, from which it passes around the curve at one end of the track and is carried back to loading position. It will be seen that at each end of the track the center rail 12 is curved out wardly toward the outside rail, as shown at 12, so that the trailing wheel 22 will follow this outward curve, and thus swing the car around into a reverse position.

The loading of the car is effected before it passes into communication with the vacuum chamber at the end of the track adjacent the vestibule 46. For this purpose a bin or hopper is provided to contain a mixture of finely ground or powdered ore, or other material, and powdered fuel. The ore in the hopper has all excess moisture removed therefrom, but while in a substantially moist state is mixed with powdered fuel, such as coal, or the like, in the proportion of about four or five per cent. by weight of coal relative to the weight of the ore. This hopper is provided with an outlet spout 66, closed by a gate 67, and the mixture of ore and fuel is discharged through this spout into the car or truck. The upper surface of the material in the car or truck is then scraped off to provide a level surface, and the car is moved forward into igniting position by propelling means, comprising a hydraulic cylinder 68, to which fluid under pressure, or other actuating fluid, is admitted through a pipe 69. This pipe leads through a four-way valve 70, connected to branch pipes 71 and 72, which are in turn connected to opposite ends of the cylinder, so that the direction of movement of the plunger 72 may be reversed by operating the valve. This plunger is connect ed to a cross head 74, and this cross head is rigidly attached to two actuating bars 75, which are mounted between the outside rails of the track 10 and are adapted to run upon rollers 76 mounted between the rails. Each of the bars 75 has two or more lever arms or latches 77 pivoted thereon at the points 78. These arms are weighted at their lower ends, as shown at 80, and are normally maintained in an inclined position, as illustrated in Fig. 3, being held against movement into a vertical position by the pins 81, which engage the lever arms above the points 78. The upper ends of the latches are provided with vertical surfaces 82, which are adapted to engage the axles 20 of the trucks, and the latches 77 are spaced apart a distance corresponding to the distance between two of the axles 20 when adj acent trucks are in substantial engagement with each other, so that two or more of the trucks are directly actuated by the bars 75 the cylinder 68 is operated to move the bar in the reverse direction, the ends 82 of the latches engage the under sides of the axles 20, and are tilted downwardly to permit the bars 75 to return to their initial positions.

As the car is moved forwardly from loading position it passes into connection with the vacuum chamber, and after moving about one cars length it occupies a position beneath the igniter 90, which comprises a hood 91 in the'form of a pyramid, having an annular flange 92 around itslow'er end adapted to seat upon and conform to the upper edges of the side walls of the car. A gas burner 93 is mounted within the hood within the flange 92, and this burner comprises a plurality of arms having burner outlets directed forwardly, so that the flame is distributed over the surface of the contents of the car. This burner is connected by a pipe 94 to a supporting tube 95 which is connected to the walls of the hood. A flexible hose 96 is connected to the tube 95 and leads through'a valve 97 "to the branch pipes 98 and 99 which are connected to the air and gas pipes 100 and 101, respectively. Another pipe 102 leading from the gas supply only is connected to a pilot light 103 by which the main gas burners are ignited when the mixture of gas and air is turned on by operating the valve 97. The hood is suspended by a hanger 105 from a chain 106 which extends upwardly over a pulley 107, and is connected at its other end to a counter-balancing Weight, as shown in Fig. 2.

When the car passes to the igniting position, the outlet of the vacuum tube 25 passes through the vestibule and into the connection with the vacuum chamber, so

that the contents of the car are under suction when the igniting hood is lowered. The gas flames impinge upon the upper surface of the contents of the car and are drawn downwardly'by the suction, so that the top layer of the charge is ignited,

When the gate opens, the suction will I be exerted upon the Water in the vestibule chamber 46, which then rises in that chamber toward the upper end of the pipe 27, and after the gate 50 closes the water will remain in an elevated position within the vestibule chamber, although usually at a lower level than that of the Water in the vacuum chamber proper due to leakage which may occur through the gates. When the gate 49 opens, the level of the water in the vestibule chamber of course falls, but

it rises again after that gate is closed. It is found, however, that the suction in the vacuum chamber remains substantially constant, and is not materially affected by the opening and closing of the gates.

It will be understood that as the cars are position.

beingfilled the contents thereof ignite and move forward continuously through a step by step movement, so that a series of cars are always in connection with the vacuum chamber shown in Figs. 1 and 2. As the sintering process takes place the suction exerted upon the mixtureof fuel and ore serves to draw the gases'of combustion into the vacuum chamber, and upon passing into the chamber the gases are subjected to a spray of cold water from the spray tube 36, so that all sediment and foreign materials are caused to settle into the water seal tank and collect in the' downwardly extending portion 31 thereof. As the cars move forwardly the scrapers 35 on the U-shaped tubes 26 collect this sediment and scrape it along to the outlet end of the tank, where it builds up in the outlet end of the tank and is gradually scraped over the end wall of the tank in the form of a pasty mass. The gases of combustion are drawn off through the pipe 39, and may be discharged to the atmosphere, or subjected to further treatment, as desired. The length of the vacuum chamber, and the progress of the cars in connection therewith, is adjusted so that the contents of each car are completely sintered by the time the car reaches the outlet end of the vacuum chamber. The car then passes through the exit chamber 56 to the dumping position, as shown particularly in Fig. 2, where the car is tilted about its axle, causing the sintered contents to fall therefrom between the outside rails of the track. An attendant is preferably stationed at this point to assist in righting the car and giving it an initial impulse, so that it will return from this elevated portion of the track to the loading position. If desired, the movements of the bars 75, by which the cars are moved in a forward direction, may be employed for giving the cars an initial impulse from the other end of the track for returning them to loading It is thought that the-operation of the apparatus has been sufficiently indicated in the foregoing description, and that a summary thereof is therefore unnecessary.

It will beunderstood that if desired the gates and the elevated portions of the track may be done away with and a circular or other suitable track substituted with a vacuum chamber extending completely around the track, so that the U-pipes of the cars are continuously connected with the vacuum chamber and are always under suction except when cut off by dampers or valves located in the individual pipes. With 1 poses of illustration, it will be understood aWhat I claimiis":

'1'. The combination in sintering apparatus, of a car adapted to receive a charge to be sintered, said car comprising a grate and an air box beneath said grate, a vacuum chamber, and means comprising a fluid-seal for forming a tight connection between said air box and said vacuum chamber.

2. The combination in sintering apparatus, of a car adapted to receive thecharge to be sintered, said car comprising a grate and an air box located opposite said grate, a

track upon which said car is adapted to .travel, a vacuumchamber extending parallel to said track, and means comprising a fluid-seal for maintaining a connection between said vacuum chamber and said air box during the travel of said car.

3. The combination in sintering apparatus, of a series of separate cars, each provided with a grate and an air box located opposite thereto with an outlet duct from said air box, a vacuum chamber, and means comprising a fluid-seal operatively connected with said duct for maintaining a connection between said ducts and said vacuum chamber during the travel of said cars.

4. The combination in sint ering apparatus, of a supporting track, a series of independent cars mounted to run on said track, a vacuum chamber extending parallel to the path of travel of said cars, each of said cars being provided with means comprising an air duct for circulating air through the charge therein, said vacuum chamber having a longitudinally extending outlet, and a liquid seal closing said outlet, said air ducts being adapted to extend through said liquid seal and establish connection with said vacuum chamber during the travel of said cars parallel thereto.

5. The combination in sintering apparatus, of a supporting track, a series 'of independent cars mounted to run on said track, a vacuum chamber extending parallel to the path of travel of said cars, each of said cars being provided with means comprising an air duct for circulating air through the charge therein, said vacuum chamber having a longitudinally extending outlet, a liquid seal closing said outlet, said air ducts being adapted to extend through said liquid seal and establish connection with said vacuum chamber during the travel of said cars parallel thereto, and means for moving said cars on said track.

6. The combination in sintering apparatus, of a supporting track, a series of independent cars mounted to run on said track, a vacuum chamber extending parallel to the path of travel of said cars, each of said cars being provided with means comprising an air duct for circulating air through the chargetherein, said vacuum chamber having a longitudinally extendin outlet, a liquid seal closing said outlet, said air ducts being adapted to extend through said liquid seal and establish connection with said vacuum chamber during the travel of said cars parallel thereto,'means for charging said cars in succession with material to be sintered, and means for igniting said charges as said cars reach said vacuum chamber.

7. The combination in sintering apparatus, of a supporting track, a series of independent cars mounted to run on said track, a vacuum chamber extending parallel to the path of travel of said cars, each of said cars belng provided with means comprising an air duct for circulating air through the charge therein, said vacuum chamber having a longitudinally extending outlet, a liquid seal closing said outlet, said air ducts being adapted to extend through said liquid seal and establish connection with said vacuum chamber during the travel of said cars parallel thereto, means for charging said cars in succession with material to be sintered, means for igniting said charges as said cars reach said vacuum chamber, and means for moving said cars along said track.

8. The combination in sintering apparatus, of a supporting track, a series of independent cars mounted torun on said track, a vacuum chamber extending parallel to the path of travel of said cars, each of said cars being provided with means comprising an air duct for circulating air through the charge therein, said vacuum chamber having a longitudinally extending outlet, a liquid seal closing said outlet, said air ducts being adapted to extend through said liquid seal and establish connection with said vacuum chamber during the travel of said cars parallel thereto, means for charging said cars in succession with material to be sintered,

means for igniting said charges as said cars reach said vacuum chamber, means for moving said cars along said track, and means for dumping said cars after they have passed said vacuum chamber.

9. The combination in sintering apparatus, of a car adapted to receive the charge to be sintered, said bar being provided with a grate and an air box beneath said grate with an outlet duct leading therefrom, a vacuum chamber having a downwardly directed inlet opening, and a receptacle containing fluid adapted to close said inlet opening, said outlet duct of said air box having a part adapted to engage said receptacle and to extend through the liquid therein int said vacuum chamber.

10. The combination in sintering apparatus, of a car adapted to receive the charge to be sintered, said car being provided with a grate and an air box beneath said grate with an outlet duct leading therefrom, a vacuum chamber extending parallel to the path of travel of said car and having a longitudinal inlet opening, and a receptacle mounted adjacent said vacuum chamber and containing fluid adapted to close said inlet opening, said outlet duct of said alr box being provided with a part adapted to extend through the liquid in said receptacle and-to maintain communication with said vacuum chamber during the travel of said-car parallel thereto.

11. The combination in sintering apparatus, of a car adapted to receive the charge to be sintered, said car being provided with a grate and an air box beneath said grate with an outlet duct leading therefrom, a vacuum chamber extending parallel to the path of travel of said car and having a longitudinal inlet opening, a receptacle mounted adjacent said vacuum chamber and containing fluid adapted to close said inlet opening, said outlet duct having a part adapted to enter the liquid in said receptacle and to communicate with said vacuum chamber above the, level of the liquid in the inlet opening thereof, and means for permitting the entry of said duct into connection with said vacuum chamber.

12. The combination in sintering apparatus, of a car adapted to receive the charge to be sintered, said car being provided with a grate and an air box beneath said grate with an outlet duct leading therefrom, a vacuum chamber extending parallel to the path of travelof said car and having. a

longitudinal inlet opening, a receptacle mounted adjacent said vacuum chamber and containing fluid adapted to close said inlet opening, said outlet duct having a part adapted to enter the liquid in said receptacle and to communicate with said vacuum chamber above the level of the liquid in the inlet opening thereof, means for permittin entry of said duct into connection wit sa-id vacuum chamber, and means for permitting disconnection of said duct from said vacuum chamber at the other end thereof.

13. The combination in sintering apparatus, of a car having means comprising an air box and an outlet duct for permitting the passage of air through the charge in said car, a vacuum chamber extending parallel to the path of travel of said car, and

- a tank containing liquid and mounted beneath said vacuum chamber, said vacuum chamber having a downward extension extending into the liquid in said tank, said outlet duct of said car having a U-shaped extension adapted to extend below the level of the liquid in said tank and to open into said vacuum chamber above the level of the liquid in the downward extension thereof.

14. The combination in sintering apparatus, of a car having means comprising an air box and an outlet duct for permitting the passage of air through the charge in said car, the vacuum chamber extending parallel to the path of travel of said car, a tank containing liquid and mounted beneath said vacuum chamber, said vacuum chamber having a downward extension extending into the liquid in said tank, said outlet duct of said car having a U-shaped extension adapted to extend below the level of the liquid in said tank and to open into said vacuum chamber above the level of the liquid in the downward extension thereof, means to permit the outlet end of said duct to pass into connection with said vacuum chamber at one end thereof, and means to permit disconnection of said outlet duct from said vacuum chamber at the other end thereof.

15. The combination in sintering apparatus, of a car having means comprising an air box and an outlet duct for permitting the passage of air through a charge therein, a track upon which said car is adapted to travel, a vacuum chamber extending parallel to said track, and a tank mounted below said vacuum chamber and containing a liquid, said vacuum chamber having a longitudinal downward extension extending into the liquid in said tank, said outlet duct having a U-shaped portion adapted to extend into the liquid in said tank and upwardly into the downward extension of said vacuum chamber.

16. The combination in sintering apparatus, of a car having means comprising an air box and an outlet duct for permitting the passage of air through a charge therein, a track upon which said car is adapted to travel, a vacuum chamber extending parallel to said track, a tank mounted below said vacuum chamber and containing a liquid, said vacuum chamber having a longitudinal downward extension extending into the liquid in said tank, said outlet duct having a U-shaped portion adapted to extend into the liquid in said tank and upwardly into the downward extension of said vacuum chamber, and an entrance chamber comprising a plurality of gates through which the upwardly extending part of said air box and an outlet duct for permitting the passage of air through a charge therein, a track upon which said car is adapted to travel, a vacuum chamber extending parallel to said track, and a tank containing a liquid mounted below said vacuum chamber, said vacuum chamber having a longitudinal downward extension extending into the liquid in said tank, said outlet duct having a U-shaped portion adapted to extend into the liquid in said tank and upwardly into the extension in said vacuum chamber, said track being elevated adjacent the end of said tank to permit the entrance of said U-shaped portion to said outlet duct into the liquid in said tank.

19. The combination in sintering apparatus, of a continuous track, a plurality of independent cars mounted on said track and adapted to contain charges of material to be sintered, means mounted adjacent said track for engaging one of said cars and propelling a plurality of said cars, means for filling said cars successively, means for igniting the charge in said cars successively, a vacuum chamber mounted parallel to said track, means for exhausting the air from said vacuum chamber, means comprising an outlet duct for permitting air to pass through the charge in each of said cars, and means comprising a liquid seal for connecting said outlet ducts with said vacuum chamber and maintaining said connection during the travel of said cars parallel thereto.

20. The combination in sintering apparatus, of a continuous track, a plurality of independent cars mounted on said track and adapted to contain charges of material to be sintered, means mounted adjacent said track for engaging and propelling a plurality of said cars, means for filling said cars successively, means for igniting the charge in said cars successively, a vacuum chamber mounted parallel to said track, means for exhausting the air from said Vacuum chamber, means comprising an outlet duct for permitting air to pass through the charge in each of said cars, means comprising a liquid seal for connecting said outlet ducts with said vacuum chamber and maintaining said connection during the travel of 'said cars parallel thereto, and a liquid spray mounted in said vacuum chamber for removing sediment from and cooling the gases drawn therethrough.

21. The combination in sintering apparatus, of a liquid-containing tank, a vacuum chamber provided with a downward extension having an inlet opening beneath the level of the liquid in said tank, a car adapted to contain a charge to be sintered, said car being provided with an air box and an outlet duct, said outlet duct having an upwardly extending part adapted to communicate with said vacuum chamber through said downward extension and a vestibule for permitting said outlet duct to entersaid vacuum chamber, said vestibule comprising a pair of gates mounted to swing about vertical axes, and means for automatically closing each of said gates after said outlet duct has passed therethrough.

22. The combination in sintering apparatus, of a liquid-containing tank, a vacuum chamber provided with a downward extension having an inlet opening beneath the level of the liquid in said tank, a car adapted to contain a charge to be sintered, said car being provided with an air box and an outlet duct, said outlet duct having an upwardly extending part adapted to communicate with said vacuum chamber through said downward extension and a vestibule for permitting said outlet duct to enter said vacuum chamber, said vestibule comprising a pair of gates mounted to swing about vertical axes, and means resiliently connecting said gates for holding one of them in closed position while the other is opened and for automatically closing either gate after said outlet duct has passed therethrough.

23. In sintering apparatus, a truck having a box-like chamber, a grate at the bottom of said chamber, a lower wall spaced from said grate to form an air box, an outlet duct connected to said air box, and inclined spacing plates mounted within the walls of said box above said grate.

24. In sintering apparatus, a truck haw ing a body provided with inwardly and downwardly converging inner walls, a grate at the lower edges of said walls, an air box below said grate, an outlet duct connected to said air box, means to ignite a charge in said car, means to exert a suction through said outlet duct after said ignition, and means to tilt said car to dump the sintered charge therefrom.

25. The combination in sintering apparatus of a receptacle adapted to receive a charge to be sintered, a chamber adajacent to which said receptacle is adapted to travel, and means comprising a fluid seal for forming an air tight communication between said chamber and said receptacle.

26. The combination in sintering apparatus of a car adapted to receive a charge to be sintered, said car having a chamber, an exhaust chamber, and means comprising a fluid seal for maintaining an air tight communication between said chamber of said car and said exhaust chamber during the travel of said car.

27. The combination in sintering apparatus of a stationary vacuum chamber having a longitudinal inlet, a liquid seal for closing said inlet, a movable car adapted to contain a charge to be sintered, and a conduit leading from said car and entering said chamber through said liquid seal.

28. The combination in sintering apparatus of a stationary'vacuum chamber having a longitudinal slotted inlet, a movable car adapted to contain a charge to be sintered,

. said car having an exhaust chamber, a conduit leading from said exhaust chamber through said inlet opening into said vacuum chamber, and means to close said inlet opening and form a seal around said conduit during the movement of said car.

29. The combination in sintering apparatus of a vacuum chamber having a longltudinal opening, a tank containing liquid for closing said opening, a car adapted to contain a charge to be sintered, a conduit leading from said car and through the liquid in said tank into said vacuum chamber, and means at the ends of said vacuum chamber for permitting said conduit to enter said opening at one end of said chamber and to emerge from said opening at the other end of said chamber. I

30. The combination in sintering apparatus of a series of sintering trucks, each having an exhaust chamber, a vacuum chamber extending parallel to the path of travel of said trucks, said vacuum chamber having an inlet opening in its under side, a vessel containing liquid adapted to close said inlet opening, a series of conduits leading from the exhaust chambers of said trucks, each of said conduits having a part adapted to extend downwardly into the liquid in said vessel and upwardly through said inlet opening, and means operated automatically by the movement of said trucks for permitting the entrance of said conduits into said Vacuum chamber and the exit of said conduits therefrom without disturbing the pressure within said vacuum chamber.

'31. The combination in sintering apparatus of a track, a series of sintering trucks adapted to travel on said track, a vacuum chamber extending longitudinally parallel to one side of said track, means at one end of said chambers for loading said trucks in succession, means adjacent said loading means for moving said series of trucks intermittently by engagement with one of them, means for forming a continuous comunication between each of said trucks and said vacuum chamber during the travel of said trucks parallel to said chamber, and means for automatically dumping the contents of each of said trucks after it has passed out gt communication with said vacuum cham- 32.. The combination in sintering apparatus of a vacuum chamber having a longitudinal inlet opening on its underside, a vessel located beneath said chamber and containing a liquid adapted to close said inlet opening, said vessel extending beyond the ends of said vacuum chamber, a track extending parallel to said vacuum chamber, a sintering truclr adapted to travel on said track, a conduit leading from said truck and having a part adapted to extend downwardly into said liquid and upwardly therefrom into said vacuum chamber during the travel of said truck, said track having a part adapted to tilt said truck and thereby elevate the downwardly extending part of said conduit over the end wall of said vessel.

' 33. The combination in sintering apparatus of an oblong continuous track, a vacuum chamber extending parallel to one side of said track, a series of trucks adapted to travel on said track, means for forming an air tight communication between each of said trucks and said vacuum chamber, means for moving said trucks from one end of said track to the other, said track having one side thereof inclined to return said trucks by gravity to the first' mentioned end of i said track.

34. The combination in sintering apparatus of a continuous track, a vacuum chamber extending parallel to a part of said track, a series of sintering trucks adapted to travel on said track, means for forming an air tight communication between each of said trucks and said vacuum chamber during the travel of said truck in one direction, means for loading said trucks in succession before they pass into communication with said vacuum chamber, means for dumping said trucks after they have passed out of communication with said vacuum chamber, and means for moving said trucks from loading position to dumping position, said track having a part thereof inclined to return said trucks by gravity from dumping position to loading position.

35. The combination in sintering appara tus of a continuous track, a vacuum chamber extending parallel to a part of said track, a series of separate unconnected sintering trucks adapted to travel on said track, means for forming an air tight communication between each of said trucks and said vacuum chamber during the travel of said trucks in one direction, means for loading said trucks in succession before they pass into communication with said vacuum chamber, means for dumping said trucks after they have passed out of communication with said vacuum chamber, and means for moving said trucks from loading position to dumping position, said track having a part thereof inclined to return said trucks by gravity from dumping position to load ing position.

36. The combination in sintering apparatus of atrack, a series of trucks mounted on, said track to receive charges of material to be sintered, a vacuum chamber adjacent said track, means for forming an air tight communication between each of said trucks and said vacuum chamber during the travel of said trucks adjacent thereto, and reciprocating feeding means mounted adjacent said track and adapted to move said series of trucks by engagement with one of them, said feeding means having a part adapted to engage one of said trucks automatically upon its forward stroke and to pass by said truck upon its return stroke.

37. The combination in sintering apparatus of a three-rail track, and a car adapted to contain'a charge to be sintered, said car having a pair of wheels mounted forwardly of the center of gravity of said car and arranged to travel on the outside rails of said track, said car being further provided with a third wheel mounted at the rear end thereof and adapted to travel on the center rail of said track, said center rail having a part thereof cut-away to permit the dropping of the rear end of the body of said car between the outside rails of said track to dump the contents thereof, said center rail having an inclined part adapted to engage said third Wheel and return said car to its upright position upon continued forward movement thereof.

In testimony whereof I have subscribed my name.

EDWARD W. DAVIS. 

